Enable handle tracing in Canary, Dev, and all debug builds of Chrome (Windows only).

sandbox/win/src/handle_closer_agent.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "sandbox/win/src/handle_closer_agent.h"
 
 #include "base/logging.h"
 #include "sandbox/win/src/nt_internals.h"
 #include "sandbox/win/src/win_utils.h"
 
 namespace {
 
+int QueryObjectTypeInformationFilter(EXCEPTION_POINTERS* exception_pointers,
+                                     NTSTATUS* exception_code) {
+  *exception_code = exception_pointers->ExceptionRecord->ExceptionCode;
+  return EXCEPTION_EXECUTE_HANDLER;

[rvargas (doing something else), 2012/10/03 03:01:16]

I'm a little concerned here about the actual handling of the exception, given
that not all exceptions are created equal. Should't we at least filter
breakpoints?

+}
+
 // Returns type infomation for an NT object. This routine is expected to be
 // called for invalid handles so it catches STATUS_INVALID_HANDLE exceptions
 // that can be generated when handle tracing is enabled.
 NTSTATUS QueryObjectTypeInformation(HANDLE handle,
                                     void* buffer,
                                     ULONG* size) {
   static NtQueryObject QueryObject = NULL;
   if (!QueryObject)
     ResolveNTFunctionPtr("NtQueryObject", &QueryObject);
 
-  NTSTATUS status = STATUS_UNSUCCESSFUL;
+  NTSTATUS exception_code = STATUS_UNSUCCESSFUL;

[rvargas (doing something else), 2012/10/03 03:01:16]

I would prefer setting exeption_code, but I don't think I fully understand your
concern.

If NtQueryOpen is patched, and there's an exception in that code, what changes?
(I mean, we are not assigning the value)... if it is being patched? If it is
executing the assignment? I don't see it. Stack corruption? let it crash :)

   __try {
-    status = QueryObject(handle, ObjectTypeInformation, buffer, *size, size);
-  } __except(GetExceptionCode() == STATUS_INVALID_HANDLE ?
-                 EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH) {
-    status = STATUS_INVALID_HANDLE;
+    return QueryObject(handle, ObjectTypeInformation, buffer, *size, size);
+  } __except(QueryObjectTypeInformationFilter(GetExceptionInformation(),
+                                              &exception_code)) {

[cpu_(ooo_6.6-7.5), 2012/10/02 19:21:37]

can't you call GetExceptionCode() from the body of the __except and not need
block 12-17 ?

[alexeypa (please no reviews), 2012/10/02 19:23:22]

GetExceptionCode() can only be called from the filter expression. It is not a
real function. Calling it from any other place will result in compiler error.

+    return exception_code;
   }
-  return status;
 }
 
 }  // namespace
 
 namespace sandbox {
 
 // Memory buffer mapped from the parent, with the list of handles.
 SANDBOX_INTERCEPT HandleCloserInfo* g_handles_to_close = NULL;
 
 bool HandleCloserAgent::NeedsHandlesClosed() {
@@ skipping 95 matching lines @@
         return false;
       if (!::CloseHandle(handle))
         return false;
     }
   }
 
   return true;
 }
 
 }  // namespace sandbox